Catheters are tubular passageways that, during a medical procedure, can be inserted into a body. Usually, the catheter is a thin, flexible tube; however, catheters can also be larger and usually more solid passageways. Catheters provide several functions, such as providing for delivery of fluids into the body, drainage of fluids out of the body, access by surgical instruments, removal of material out of the body, and more.
The process of inserting a catheter is referred to as “catheterization.” A catheter left inside the body temporarily, e.g., a few hours or less, is referred to as an “acute” device. A catheter left inside the body for an extended period of time, e.g., days or weeks, is referred to as a “chronic” device.
One use of catheters is to provide delivery of drugs to treatment areas of the brain. These catheters are inserted through the soft brain tissue and guided to the location where pharmaceuticals or other fluid treatments are to be delivered. One problem that occurs during catheter insertion is clogging of the tip of the catheter fluid passageway. This clogging is, in large part, due to the extremely soft consistency of living brain tissue, which readily separates and pushes into the open end of the catheter.
Medically-therapeutic fluid is delivered through the catheter and to the treatment site by manual compression of a syringe or delivery by a mechanical pump. However, if the tip of the catheter is clogged, fluid cannot flow to the delivery site. The effect is that a sharp increase in pressure builds up inside the catheter. If the pressure releases all at once, i.e., the clog and fluid forcefully and instantly exit the tip of the catheter, tissue will likely be decimated, potentially causing damage, and in some cases severe damage, to the brain. Again, procedures to the brain are particularly susceptible to this type of damage as neural tissue is soft and can easily be destroyed by a pressurized liquid force.
Additionally, if the fluid does not exit the catheter properly, instead of being delivered to the treatment site, the fluid is forced away from the treatment site, travels back out of the catheter entry path (between the exterior of the catheter and the brain tissue), and out of the brain. This is highly undesirable, as neurological medicines are often delivered in very small doses and, therefore, measured with extremely high precision. Any loss of fluid destroys the dosage calculation, as it is virtually impossible to determine the amount of medicine lost or the contents of a portion of a compound lost. In addition, neurological medicines are often very expensive and, for at least this reason, losses should be avoided.
Although catheters used for neurological treatments are more susceptible to clogging than those used for treatment of other areas, clogging is still highly likely and can cause damage, can introduce uncertainty to treatment procedures, and can result in unnecessary financial waste.
Therefore, a need exists to overcome the problems with the prior art as discussed above.